Add editor localization support (WIP)

Adding editor localization support.

- Specific language in editor setting
![](http://oi62.tinypic.com/13zzndv.jpg)

- Reading translation strings from [editor setting folder]/lang/[locale]/editor.po
![](http://oi62.tinypic.com/155kl05.jpg)
pls blame Goolge for bad translation :)

![](http://oi62.tinypic.com/2qw0cpi.jpg)

po template generated from xgettext and translated in POEditor